This invention relates to unsymmetrical azo compounds, unsymmetrical hydrazo compounds, processes for preparing these compounds and processes utilizing these compounds, which azo and hydrazo compounds are characterized by having a tertiary carbon atom joined to one of the azo or hydrazo nitrogens.
Symmetrical azo compounds having a tert-carbon atom joined to each zero azo nitrogen are known:
T. e. stevens, J. Org. Chem. 26, 2531 (1961). PA1 E. farenhorst and E. C. Kooyman, Rec. Trav. Chim. 72, 993 (1953). PA1 S. f. nelson and P. D. Bartlett, J. Am. Chem. Soc. 88, 137, 143 (1966). PA1 M. c. chaco and N. Rabjohn, J. Org. Chem. 27, 2765 (1962). PA1 D. c. iffland, L. Salisbury, and W. R. Schafer, J. Am. Chem. Soc. 83, 747 (1961). PA1 D. y. curtin and J. A. Ursprung, J. Org. Chem. 21, 1221 (1956). PA1 C. g. overberger and A. V. DiGiulio, J. Am. Chem. Soc. 80, 6562 (1958); ibid 81, 2154 (1959). PA1 H. wieland, et al., Ann. 514, 145 (1934). PA1 Thiele, B. 28, 2600. PA1 Angeli, Rome Atti Accad Tincei 26 I, 95 (1917). PA1 Thiele and Strange, Ann 283, 33 (1894). PA1 D. neighbors et al., J. Am. Chem. Soc. 44, 1557 (1922). PA1 a. R is the radical (R").sub.3 C with R" being a lower alkyl, aralkyl or phenyl radical and not more than one phenyl is present; and PA1 b. R.sub.1 and R.sub.2 are lower aliphatic or cycloaliphatic radicals and together may form an alkylene biradical. PA1 1. 2-t-cumylazo-2-hydroxypropane PA1 2. 2-t-butylazo-2-hydroxy-tetradecane PA1 3. 1-t-butylazo-1-cyclopropyl-1-hydroxyethane PA1 4. 1-t-adamantylazo-1cyclohexyl-1-hydroxyethane PA1 5. 1-[t-(.alpha.-methyl-.alpha.-ethyl-nonyl)azo]-1-cyclododecyl-1-hydroxyetha ne PA1 6. 1-[t-(.alpha.,.alpha.-dimethyl-.beta.-phenylethyl)azo]-1-cyclopentyl-1-hyd roxyethane PA1 7. 1-[t-(1,1-dimethyl-7-phenylheptyl)azo]-1-cyclooctyl-1-hydroxyethane PA1 8. 1-[t-(p-t-butylcumyl)azo]-1-norborn-2-yl-1-hydroxyethane PA1 9. 1-[t-(1-(phenanthr-2yl)-1-methylethyl)azo]-1-adamant-2-yl-1-hydroxyethane PA1 10. 2-[t-(decalylazo)]-2-hydroxy-1-phenylpropane PA1 11. 3-[t-(1-methylcyclopentyl)azo]-3-hydroxy-1-naphth-2-ylbutane PA1 12. 2-[t-(.alpha.-methyl-.alpha.-ethylpropyl)azo]-2-hydroxy-1-(p-t-butyl)pheny lpropane PA1 13. 1-[t-(.alpha.,.alpha.-diethylpropyl)azo]-1-hydroxy-1-phenylethane PA1 14. 2-t-(amylazo)-2-hydroxy-5-phenylpentane PA1 15. 1-[t-(.alpha.,.alpha.-dimethylpentyl)azo]-1-hydroxy-1-phenanthr-2-ylethane PA1 16. 1-[t-(.alpha.-methyl-.alpha.-cyclopropylethyl)azo]-1-hydroxyl-1-naphth-2-y lethane PA1 17. 2-[t-(.alpha.,.alpha.-dimethyl-.beta.-phenylethyl)azo]-2-hydroxybutane PA1 18. 2-[t-(1-methylcyclododecyl)azo]-2-hydroxypropane PA1 19. 1-t-(.alpha.-methyl.alpha.-cyclododecylethyl)azo]-1-hydroxycyclobutane PA1 20. 2-[t-(.alpha.-methyl-.alpha.-cyclooctylethyl)azo]-2-hydroxy(2.2.2-bicycloo ctane) PA1 21. 1-[t-(.alpha.-methyl-.alpha.-(norborn-2-yl)ethyl)azo]-1-hydroxycyclododeca ne PA1 22. 1-[t-(.alpha.-methyl-.alpha.-(2.2.2-bicyclooct-2-yl)azo]-1-hydroxycyclooct ane PA1 23. 1-[t-adamantyl-.alpha.-methylethyl)azo]-1-hydroxycyclodecane PA1 24. 2-[t-(1,1-dimethyl-4-phenylbutyl)azo]-2-hydroxynorbornane PA1 25. 2-[t-(.alpha.-methyl-.alpha.-naphth-2-ylethyl)azo]-2-hydroxyadamantane PA1 26. 2-[t-(1-methylcyclopropyl)azo]-2-hydroxy-4-methyl-4-phenoxypentane PA1 27. 2-[t-(2-methylnorborn-2-yl)azo]-2,4-dihydroxy-4-methylpentane PA1 28. 2-[t-(.alpha.,.alpha.-dimethyl-.gamma.-naphth-2-ylpropyl)azo]-2,5-dihydrox ypentane PA1 29. Phenyl 5-[t-(.alpha.-methyl-.alpha.-naphth-2-ylethyl)azo]-5-hydroxyhexanoate PA1 30. 1-[t-(.alpha.-methyl-.alpha.-(p-methylphenyl)ethyl)ethyl)azo]-1-hydroxy-1- (p-chlorophenyl)ethane PA1 31. 1-[t-(1-methylcyclohexyl)azo]-1hydroxy-1-(m-bromophenyl)-ethane PA1 32. 1-[t-(1-methylcyclooctyl)azo]-1-hydroxy-1-(p-fluorophenyl)ethane PA1 33. 1-[t-(butyl)azo]-1-hydroxy-1-(p-iodophenyl)propane PA1 34. 3-[t-(butyl)azo]-3-hydroxy-1-benzoyloxybutane PA1 35. 1-[t-(amyl)azo]-1-hydroxy-1-(p-cyanophenyl)ethane PA1 36. 2-[t-(1,1,3,3-tetramethylbutyl)azo]-2-hydroxy-5-aminopentane PA1 37. 1-(1,1,3-trimethylbutyl)azo]-1-hydroxy-1-cyclobutylethane PA1 38. 2-[t-(.alpha.,.alpha.-dimethylbenzyl)azo]-2-hydroxytetralin PA1 39. 4-[t-(.alpha.,.alpha.-diisobutylethyl)azo]-4-hydroxy-2,7-dimethylheptane PA1 40. 2-[t-(1,1,3,3-tetramethylbutyl)azo]-2-hydroxy-3,3-dimethylbutane PA1 41. 2-[t-(.alpha.,.alpha.-dimethyl-p-chlorobenzyl)azo]-2-hydroxy-4,4-dimethylp entane PA1 42. 2-[t-(.alpha.,.alpha.-dimethyl-m-bromobenzyl)azo]-2-hydroxydecane PA1 43. 2-[t-(.alpha.,.alpha.-dimethyl-p-cyanobenzyl)azo]-2-hydroxyindane PA1 44. 1-[t-(2-methyltetral-2-yl)azo]-1-hydroxy-1-(fur-2-yl)-ethane PA1 45. 1-[t-(.alpha.,.alpha.-diisobutylethyl)azo]-1-hydroxy-1-(tetrahydrofur-2-yl )ethane PA1 46. 1-[t-(.alpha.,.alpha.,.beta.,.beta.-tetramethylpropyl)azo]-1-hydroxy-1-(py rid-4-yl)ethane PA1 47. 1-[t-(.alpha.,.alpha.-dibenzylethyl)azo]-1-hydroxy-1-(thiophen-2-yl)ethane PA1 48. 1-[t-(2-methylindan-2-yl)azo]-1-hydroxy-1-(anthracen-9-yl)ethane PA1 49. 1-[t-(.alpha.,.alpha.-dicyclopropylethyl)azo]-1-hydroxy-1-(pyrid-2-yl)etha ne PA1 50. 2-[t-(.alpha.,.alpha.-dicyclohexylethyl)azo]-2-hydroxy-3-methylbutane PA1 51. 2-t-cumylazo-2-bromopropane PA1 52. 2-t-butylazo-2-chlorotetradecane PA1 53. 1-t-butylazo-1-cyclopropyl-1-bromoethane PA1 54. 1-t-adamantylazo-1-cyclohexyl-1-chloroethane PA1 55. 1-[t-(.alpha.-methyl-.alpha.-ethylnonyl)azo]-1-cyclododecyl-1-chloroethane PA1 56. 1-[t-(.alpha.,.alpha.-dimethyl-.beta.-phenylethyl)azo]-1-cyclopentyl-1-chl oroethane PA1 57. 1-[t-(1,1-dimethyl-7-phenylheptyl)azo]-1-cyclooctyl-1-chloroethane PA1 58. 1-[t-(p-t-butylcumyl)azo]-1-norborn-2-yl-1-chloroethane PA1 59. 1-[t-(1-(phenanthr-2-yl)-1-methylethyl)azo]-1-adament-2-yl-1-chloroethane PA1 60. 2-[t-(decalylazo)]-2-chloro-1-phenylpropane PA1 61. 3-[t-(1-methylcyclopentyl)azo]-3-chloro-1-naphth-2-yl-butane PA1 62. 2-[t-(.alpha.-methyl-.alpha.-ethylpropyl)azo]-2-chloro-1-(p-t-butyl)-pheny lpropane PA1 63. 1-[t-(.alpha.,.alpha.-diethylpropyl)azo]-1-chloro-1-phenylethane PA1 64. 2-t-(amylazo)-2-chloro-5-phenylpentane PA1 65. 1-[t-(.alpha.,.alpha.-dimethypentyl)azo]-1-chloro-1-phenanthr-2-yl-ethane PA1 66. 1-[t-(.alpha.-methyl-.alpha.-cyclopropylethyl)azo]-1-chloro-1-naphth-2-yle thane PA1 67. 2-[t-(.alpha.,.alpha.-dimethyl-.beta.-phenylethyl)azo]-2-chlorobutane PA1 68. 2-[t-(1-methylcyclododecyl)azo]-2-chloropropane PA1 69. 1-[t-(.alpha.-methyl-.alpha.-cyclododecylethyl)azo]-1-chlorocyclobutane PA1 70. 2-[t-(.alpha.-methyl-.alpha.-cyclooctylethyl)azo]-2-chloro-(2.2.2.-bicyclo octane) PA1 71. 1-[t-(.alpha.-methyl-.alpha.-(norborn-2-yl)ethyl)azo]-1-chlorocyclododecan e PA1 72. 1-[t-(.alpha.-methyl-.alpha.-(2.2.2-bicyclooct-2-yl)azo]-1-chlorocycloocta ne PA1 73. 1-[t-(.alpha.-t-adamantyl-.alpha.-methylethyl)azo]-1-chlorocyclodecane PA1 74. 2-[t-(1,1-dimethyl-4-phenylbutyl)azo]-2-chloronorbornane PA1 75. 2-[t-(.alpha.-methyl-.alpha.naphth-2-ylethyl)azo]-2-chloroadamantane PA1 76. 2-[t-(1-methylcyclopropyl)azo]-2-chloro-4-methyl-4-phenoxpentane PA1 77. 2-[t-(2-methylnorborn-2-yl)azo]-2-chloro-4-hydroxy-4-methylpentane PA1 78. 2-t-(.alpha.,.alpha.-dimethyl-1-naphth-2-ylpropy)azo]-2-chloro-5-hydroxype nane PA1 79. Phenyl 5-[t-(.alpha.-methyl-.alpha.-naphth-2-ylethyl)azo]-5-chlorohexanoate PA1 80. 1-[t-(.alpha.-methyl-.alpha.-(p-methyphenyl)ethyl)azo]-1-chloro-1-(p-chlor ophenyl)ethane PA1 81. 1-[t-(1-methylcyclohexyl)azo]-1-chloro-1-(m-bromophenyl)ethane PA1 82. 1-[t-(1-methylcyclooctyl)azo]-1-chloro-1-(p-fluorophenyl)ethane PA1 83. 1-[t-(butyl)azo]-1-chloro-1-(p-iodophenyl)propane PA1 84. 3-[t-(butyl)azo]-3-chloro-1-benzoyloxybutane PA1 85. 1-[t-(amyl)azo]-1-chloro-1-(p-cyanophenyl)ethane PA1 86. 2-[t-(1,1,3,3-tetramethylbutyl)azo]-2-chloro-5-aminopentane PA1 87. 1-[t-(1,1,3-trimethylbutyl)azo]-1-chloro-1-cyclobutylethane PA1 88. 2-[t-(.alpha.,.alpha.-diiethylbenzyl)azo]-2-chlorotetralin PA1 89. 4-[t-(.alpha.,.alpha.-diisobutylethyl)azo]-4-chloro-2,7,dimethylheptane PA1 90. 2-[t-(1,1,3,3-tetramethylbutyl)azo]-2-chloro-3,3-dimethylbutane PA1 91. 2-[t-(.alpha.,.alpha.-dimethyl-p-chlorobenzyl)azo]-2-chloro-4,4-dimethylpe ntane PA1 92. 2-[t-(.alpha.,.alpha.-dimethyl-m-bromobenzyl)azo]-2-chlorodecane PA1 93. 2-[t-(.alpha.,.alpha.-dimethyl-p-cyanobenzyl)azo]-2-chloroindane PA1 94. 1-[t-(2-methyltetral-2-yl)azo]-1-chloro-1-(fur-2-yl)ethane PA1 95. 1-[t-(.alpha.,.alpha.-diisobutylethyl)azo]-1-chloro-1(tetrahydrofur-2-yl)e thane PA1 96. 1-[t-(.alpha.,.alpha.,.beta.,.beta.-tetramethylpropyl)azo]-1-chloro-1-(pyr id-4-yl)ethane PA1 97. 1-[t-[(.alpha.,.alpha.-dibenzylethyl)azo]-1-chloro-1-(thiophen-2-yl)ethane PA1 98. 1-[t-(2-methylindan-2yl)azo]-1-chloro-1-(anthracen-9-yl)ethane PA1 99. 1-[t-(.alpha.,.alpha.-dicyclopropylethyl)azo]-1-chloro-1-(pyrid-2-yl)ethan e PA1 100. 2-[2-(.alpha.,.alpha.-dicyclohexylethyl)azo]-2-chloro-3-methylbutane PA1 Canadian Pat. No. 655,296 issued Jan. 1, 1963. PA1 J. c. bevington and A. Wahid, Polymer 3, 585 (1962); ibid 4, 129 (1963). PA1 D. neighbors, et al., J. Am. Chem. Soc. 44, 1561 (1922). PA1 H. zollinger, "Azo and Diazo Chemistry, Aliphatic and Aromatic Compounds", Interscience, New York, N.Y., 1961, p. 327. PA1 Goldschmidt and Acksteiner, Ann. 618, 173 (1958) PA1 British Pat. No. 988,253 issued Apr. 7, 1961 to Monsanto Co. PA1 Canacian Pat. No. 750,380 issued Jan. 10, 1967 to Monsanto Co. PA1 H. bock and J. Kroner, Chem. Ber. 99, 2039 (1966). PA1 K. e. cooper and E. H. Ingold, J. Chem. Soc. 1926, 1894. ##STR31## It was unknown, prior to the present work, that a mono azo ester, such as [E], would react with primary and secondary amines (including ammonia) to form the corresponding azoformamide. PA1 J. lakritz, "The Synthesis and Reactions of Sterically Hindered Hydrazines; And the Acid Catalyzed Rearrangement of Tertiary cyclic Azides", University of Michigan, Ph.D. thesis, 1960, University Microfilms, Inc., Mio 60-6898. ##STR34## The [J] compounds cannot be oxidized to azo compounds. The formation of [G] rather than [J] when R is a tertiary alkyl group is due to the bulky nature of the tertiary group. This has been previously reported and [G] compounds are known but have never been oxidized to the azo compounds. The azo compounds [H] are very unstable and therefore difficult to isolate. PA1 A. andraca, Anales quim farm 1941, p. 15. PA1 Pellizzari, Gazz. chim. ital. 16, 302 (1888) PA1 Pinner, Ber., 20, 2359 PA1 Beilstein, 15, 287 PA1 C. vogelsang, Rec. trav. chim. 62, 5 (1943) PA1 K. a. taipale and P.V. Usachev, J. Russ. PA1 Chem. Soc. 62, 1241-58 (1930)
Unsymmetrical azo compounds where a tert-carbon atom is joined to one azo nitrogen are known. Illustrative compounds of this type, none coming within the scope of the invention are given in:
The above compounds are in general difficult to prepare, or are so stable that they are not useful as free radical generators or as blowing agents for plastic foams.
2,2'-AZOBISISOBUTYRONITRILE IS COMMERCIALLY AVAILABLE. This compound has the structure. ##STR2## It has many shortcomings. It is a toxic solid. Moreover, the decomposition residue is a highly toxic solid. Thus, it presents a toxic dusting problem when used in commercial operations and extreme precautions are required in its handling. It is not used in many applications for which it is suited because other areas at the manufacturing site cannot tolerate even the remote chance of exposure to such toxic dust. This is especially true when manufacturing goods for the food and drug packaging industries and many other goods for the household consumer. It cannot be used as a blowing agent for the great majority of the plastic foam market due to the high levels of the toxic residue left in the foamed product. It is insoluble in petroleum hydrocarbon solvents and possesses very low or limited solubility in most of the organic common solvents such as aromatic hydrocarbons, dioxane, alcohol, ether and carbon tetrachloride. This insoluble nature eliminates its use for many applications for which it would otherwise be suitable. It presents problems of metering, incorporate, mixing, dispersing, etc. and necessitates the use of a solvent that in many cases is not ideally suited for the particular application.
The new compositions of the present invention eliminate these problems. Most of the new compositions are liquids and are soluble in petroleum hydrocarbon and most of the other common organic solvents. Thus, no dusting, metering, incorporating, mixing, and dispersing problems are encountered in using these new compositions. Also the new compositions and their decomposition residues have chemical structures that suggest that they are, for the most part, significantly less toxic. Preliminary toxicological studies on the new compositions made in Examples I and IV, set out later, and the decomposition residue of the Example I product indicate that they are significantly less toxic than IXA and its decomposition residue. The less toxic nature of the new compositions coupled with their liquid and high solubility properties allows them to be used in many applications where IXA cannot be used.
Unsymmetrical tert-carbon containing hydrazo compounds are known. Illustrative literature showing the prior art types of these compounds is presented: